In buildings and so forth occupied by multiple offices or multiple tenants, so-called split system air conditioners are often used to effectively regulate the air-conditioned environments inside the building. In split system air conditioners, multiple air conditioners are installed inside a building, so in a building in which split system air conditioners are used, the proportion of the consumed energy of the air conditioners with respect to the consumed energy of the building overall tends to increase as the number of air conditioners installed increases.
Meanwhile, in recent years, reducing consumed energy has been raised. For example, as described in Japanese Patent Publication No. 2004-85087, a technology that estimates the consumed energy of an air conditioner and judges from the estimation result whether or not there is waste in the operation of the air conditioner is known.